From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270085AbTG3KfV (ORCPT ); Wed, 30 Jul 2003 06:35:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270218AbTG3KfV (ORCPT ); Wed, 30 Jul 2003 06:35:21 -0400 Received: from mx2.elte.hu ([157.181.151.9]:6024 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S270085AbTG3KfR (ORCPT ); Wed, 30 Jul 2003 06:35:17 -0400 Date: Wed, 30 Jul 2003 12:34:39 +0200 (CEST) From: Ingo Molnar Reply-To: Ingo Molnar To: Andrea Arcangeli Cc: Andrew Morton , , Subject: Re: PATCH: Race in 2.6.0-test2 timer code In-Reply-To: <20030730083726.GE23835@dualathlon.random> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 30 Jul 2003, Andrea Arcangeli wrote: > I never did any 2.6 patch, so it maybe a different thing what you've > seen, not what I applied to 2.4. Infact even the 2.4 patch isn't from > me. the 2.4 timer-scalability patches do have a problem: due to TIMER_BH the actual timer expiry can happen on a different CPU, which opens up a del_timer()/add_timer() race in the itimer code. Your patch closes that hole. But on 2.6 the timer will run precisely on the CPU it was added, so i think the race is not possible. Ingo